title: Rice oxalate oxidase gene driven by green tissue-specific promoter increases tolerance to sheath blight pathogen (Rhizoctonia solani) in transgenic rice.
abstract: Rice sheath blight, caused by the necrotrophic fungus Rhizoctonia solani, is one of the most devastating and intractable diseases of rice, leading to a significant reduction in rice productivity worldwide. In this article, in order to examine sheath blight resistance, we report the generation of transgenic rice lines overexpressing the rice oxalate oxidase 4 (Osoxo4) gene in a green tissue-specific manner which breaks down oxalic acid (OA), the pathogenesis factor secreted by R. solani. Transgenic plants showed higher enzyme activity of oxalate oxidase (OxO) than nontransgenic control plants, which was visualized by histochemical assays and sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Transgenic rice leaves were more tolerant than control rice leaves to exogenous OA. Transgenic plants showed a higher level of expression of other defence-related genes in response to pathogen infection. More importantly, transgenic plants exhibited significantly enhanced durable resistance to R. solani. The overexpression of Osoxo4 in rice did not show any detrimental phenotypic or agronomic effect. Our findings indicate that rice OxO can be utilized effectively in plant genetic manipulation for sheath blight resistance, and possibly for resistance to other diseases caused by necrotrophic fungi, especially those that secrete OA. This is the first report of the expression of defence genes in rice in a green tissue-specific manner for sheath blight resistance.
authors.affiliation: Plant Molecular Biology and Biotechnology Laboratory, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India.
authors.forename: Kutubuddin A
authors.initials: KA
authors.lastname: Molla
authors.forename: Subhasis
authors.initials: S
authors.lastname: Karmakar
authors.forename: Palas K
authors.initials: PK
authors.lastname: Chanda
authors.forename: Satabdi
authors.initials: S
authors.lastname: Ghosh
authors.forename: Sailendra N
authors.initials: SN
authors.lastname: Sarkar
authors.forename: Swapan K
authors.initials: SK
authors.lastname: Datta
authors.forename: Karabi
authors.initials: K
authors.lastname: Datta
mesh_terms: D060467:Disease Resistance / Q000235:genetics*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D005966:Glucuronidase / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D012275:Oryza / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000276:immunology; D019815:Oxalic Acid / Q000494:pharmacology; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000235:genetics / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000382:microbiology; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012232:Rhizoctonia / Q000187:drug effects / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D019815:Oxalic Acid; D010088:Oxidoreductases; C020598:oxalate oxidase; D005966:Glucuronidase; D010650:Phenylalanine Ammonia-Lyase